A combine is known from Patent Document 1 that is provided, within a grain tank, with a moisture sensor for crushing grains flowing from a grain supply opening that leads to the grain tank, between rotating electrode rollers, and detecting an electrical resistance value of the grains in a crushed state. A grain moisture content measuring means for measuring the grain moisture content based on this electrical resistance value is provided in a control apparatus. This grain moisture content measuring means computes the grain moisture content based on the electrical resistance value from the moisture sensor, using a given computing equation for conversion into grain moisture content, and an LUT (look-up table). Specifically, the computing equation for conversion into grain moisture content, which is called a working curve, and the LUT are registered in advance for each type and breed of crop to be harvested, in a ROM.
Patent Document 2 discloses an agricultural management system that receives, from a combine, harvest position data, which indicates a harvest work position, as farmland information, harvest amount data, which indicates the harvest amount of farm produce harvested in a farmland, as farm produce information, and quality data, which indicates the quality thereof, and sends agricultural evaluation data to a user by performing agricultural evaluation on the farmland based on the farmland information and the farm produce information.